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Ribbed Mussel Study Status JBTF.pdf

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Ribbed Mussel Study Status JBTF.pdf

  1. 1. DEP Ribbed Mussel Study Jamaica Bay LTCP Jamaica Bay Task Force Meeting May 10, 2022 John McLaughlin Managing Director Office of Ecosystem Services, Green Infrastructure and Research
  2. 2. 2 Agenda 1. Ribbed Mussel Study Overview 2. Literature Review 3. Microcosm Bench-top Experimental Results 4. Mesocosm Lab Testing Experimental Protocol 5. In-Situ Pilot Study Considerations
  3. 3. 3 1 Literature Review 2 Microcosm Bench-top Testing 3 Mesocosm Lab Testing 4 In-Situ Pilot Study Ribbed Mussel Study Overview 1 2 3 4
  4. 4. 4 Literature Review Intent Gain further understanding of: • Filtration capabilities of Ribbed Mussels • How Ribbed Mussels have been used in other studies to improve water quality • Using mussels in a sub-tidal setting 1
  5. 5. 5 Literature Review Conclusions • Ribbed mussels are capable of filtering out particles as small as bacteria (< 1 micron) from water • Additional studies recommended to evaluate bacterial removal (E. coli and Entero) via filtration by Ribbed Mussels Literature Reference Particle Size Filtration Efficiency Langdon & Newell (1990) < 2 µm 15.8% Newell & Krambeck (1995) Not specified 30-35% Riisgard (1988) 2 µm 70% Wright et al (1982) 0.2-0.4µm 30% 0.4-0.6µm 86% 1
  6. 6. 6 Microcosm Experiments Intent • Confirm literature findings and applicability to the environmental conditions of Bergen and Thurston Basins • Experiments conducted: • Filtration efficacy • Gradual salinity changes • Fate of bacteria • Respiration • Effect of chlorine 2
  7. 7. 7 Filtration Efficacy • Ribbed Mussels effectively filtered bacteria across the environmental conditions of Bergen and Thurston Basins • In a beaker, Ribbed Mussels shown to filter 56% to 94% of pathogens • Low salinity was the only parameter that temporarily depressed filtration efficiency 2 (5, 12.5 ppt) (15, 21, 28 ℃) (30-35, 55-75, 70+ mm) (algae and silt levels) (1, 3, 6 mg/L) (5, 12.5, 20, 25 ppt)
  8. 8. 8 Gradual Salinity Changes • Pathogen clearance rates were temporarily depressed during low salinity events, but quickly rebounded as salinity levels recovered 2
  9. 9. 9 • A large fraction of the pathogens cleared were removed from the environment Fate of Bacteria 2 To facilitate pseudofeces and feces collection, ribbed mussels were suspended horizontally over a petri dish.
  10. 10. 10 • Ribbed Mussels exerted an oxygen demand of 0.678 mg O2/hr/g dry tissue • Based on the mussels’ low respiration rate, full scale deployment of Ribbed Mussels will not adversely impact the dissolved oxygen levels in either Bergen or Thurston Basins Respiration 2
  11. 11. 11 • Activity and survivorship of juvenile Ribbed Mussels and were not adversely impacted when exposed to acute and chronic chlorine residuals Effect of Chlorine on Juvenile Ribbed Mussels 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 250 100 10 0 (Control) Percent Survivorship at Day 4 Chlorine Concentration (ppb) Survivorship of Juvenile Ribbed Mussel 2
  12. 12. 12 • Activity and survivorship larvae were not adversely impacted when exposed to acute chlorine residuals; however chronic exposure to high chlorine levels may lower larvae survival rates Effect of Chlorine on Larvae 2 Chlorine Concentration
  13. 13. 13 Microcosm Conclusions • Mussels effectively filter bacteria across the environmental conditions of Bergen and Thurston Basins • Filtration was only temporarily limited in low salinity waters, but quickly rebounded as salinity levels recovered • A large fraction of the pathogens cleared were removed from the environment • Full scale deployment of Ribbed Mussels will not adversely impact the dissolved oxygen levels in Jamaica Bay • Activity and survivorship of juvenile Ribbed Mussels and larvae were not adversely impacted when exposed to acute chlorine residuals 2
  14. 14. 14 Mesocosm Experiments Intent (currently underway) • Scale-up from beaker microcosm to a mesocosm tank to test under flow- through conditions Ribbed Mussel holding tank with circulating seawater (top). Tank setup showing the main, collector, and header tanks (bottom). 3
  15. 15. 15 Mesocosm Experiments Ribbed Mussel Density: • Medium Density (720 RM) • Max Density (1,440 RM) Bacteria Pulse and Freshwater Input (1,440 RM): • Bacteria Pulse • Bacteria Stepped Feed & Freshwater Input • Spatial Arrangement Variation with Bacteria Step Feed & Freshwater Input • Unfiltered seawater, Spatial Arrangement Variation with Bacteria Step Feed & Freshwater Input Freshwater input at the head-end of the tank (top). Close-up of Ribbed Mussels suspended in mesh bags (bottom). 3
  16. 16. 16 Sampling Protocol • The experiment ran for 4 hours with samples taken every 20 mins from the front (influent) and back (effluent) of the tank. Samples were taken before the bacteria was added to serve as blanks. • Samples were analyzed via flow cytometry and additional samples were analyzed using standard IDEXX Enterolert techniques used for measuring Enterococci. Influent sampling locations and salinity sensor (top). Effluent sampling locations (bottom). 3
  17. 17. 17 In-Situ Pilot Study Intent • The next phase will scale up to 75,000 RM deployed in Bergen or Thurston Basin • Ongoing discussions with hatcheries to initiate large scale spawning • Recent field visit observed Ribbed Mussels in Bergen Basin • Structures will be installed to monitor natural recruitment of mussels Ribbed mussels (top). Deployment sites in Bergen Basin under consideration (bottom). Deployment Sites Under Consideration 4
  18. 18. THANK YOU!

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